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Associate Professor Tony Verboom


Phone: 021 650 3398 
Room No.: 3.11 (HW Pearson Building)

Head of Department


Director, Bolus Herbarium











Core research interests

Focussing on the southern African flora, especially the hyper-diverse Greater Cape flora, my research is motivated by an interest in patterns of diversity and the historical and contemporary processes by which diversity is generated, maintained and organized. As such, it can be structured into four broad themes:

  • documenting the diversity of plant lineages and floristic assemblages;
  • understanding the processes by which diversity is generated and maintained;
  • exploring the evolution of resource acquisition traits and how such traits define plant niches and distributions; and
  • understanding the historical and contemporary factors that determine the distribution and organization of floristic diversity at the community and landscape level.

My research is integrative, spanning the fields of evolutionary biology, ecology, systematics and biogeography. Current research in my lab is centred around the use of next generation sequencing data to address the mechanistic basis of population and species differentiation in the Greater Cape Floristic Region. I am also embarking on a new program of research, exploring the use of phylogenies and population genetic data to identify climatic refugia in the Greater Cape Floristic Region.

Professional career


 BSc (Hons), Cape Town


 MSc, Cape Town


 Assistant Scientific Officer, Royal Botanic Gardens Kew


 PhD, Cape Town


 Postdoctoral fellow, University of Missouri-Saint Louis


 Lecturer, University of Cape Town


 Senior lecturer, University of Cape Town


 Associate professor, University of Cape Town


Undergraduate teaching

At the undergraduate level (BSc), I currently teach modules on niche theory and community assembly, vascular and flowering plant diversity, global species richness patterns, and comparative and macroevolutionary analysis. At the honours level, I currently teach a module on phylogenetic ecology. 

Postgraduate student supervision

Graduated MSc and PhD students

  • Jack Henning, MSc (coursework and dissertation) 2003*, principal supervisor
  • Margaret Herron, MSc (coursework and dissertation) 2006*, principal supervisor
  • Tracey Nowell, PhD 2008, principal supervisor
  • Matthew Britton, MSc (dissertation) 2010, principal supervisor
  • Simon Power, MSc (dissertation) 2011, co-supervisor
  • Timothy Moore, MSc (dissertation) 2011*, principal supervisor
  • Megan Yates, MSc (dissertation) 2011*, co-supervisor
  • Jasper Slingsby, PhD 2011, principal supervisor
  • Vera Hoffmann, MSc (dissertation) 2012*, principal supervisor
  • Ignatious Matimati, PhD 2013, co-supervisor
  • Joanne Bentley, MSc (dissertation) 2014*, principal supervisor
  • Jack Viljoen, MSc (dissertation) 2016*, co-supervisor
  • Seth Musker, MSc (dissertation) 2017*, principal supervisor
  • Simon Power, PhD 2018, co-supervisor
  • Zaynab Shaik, MSc (dissertation) 2019*, principal supervisor
  • Joel Lewis, MSc (dissertation) 2019, co-supervisor
  • Daniel Zhigila, PhD 2020, co-supervisor
  • Lara Wootton, MSc (dissertation) 2021*, principal supervisor

Current research students

  • Ruan van Mazijk, MSc (dissertation), co-supervisor
  • Graham Duncan, PhD, principal supervisor
  • Thaabiet Parker, MSc (dissertation), principal supervisor
  • Seth Musker, PhD, co-supervisor
  • Zaynab Shaik, PhD, co-supervisor



Peer reviewed journal articles

Musker SD, Ellis AG, Schlebusch SA, Verboom GA. In press. Niche specificity influences gene flow across fine-scale habitat mosaics in Succulent Karoo plants. Molecular Ecology.

Bouchenak-Khelladi Y, February EC, Verboom GA, Boucher FC. In press. C4 grass functional traits are correlated with biotic and abiotic gradients in an African savanna. Plant Ecology.

Verboom GA, Boucher FC, Ackerly DD, Wootton LM, Freyman WA. 2020. Species selection regime and phylogenetic tree shape. Systematic Biology 69: 774-794.

Boucher FC, Quatela AS, Ellis AG, Verboom GA. 2020. Diversification rate vs. diversification density: decoupled consequences of plant height for diversification of Alooideae in time and space. PLoS ONE 15: e0233597.

Zhigila DA, Verboom GA, Muasya AM. 2020. An infrageneric classification of Thesium (Santalaceae) based on molecular phylogenetic data. Taxon 69: 100-123.

Power SC, Verboom GA, Bond WJ, Cramer MD. 2019. Does a trade-off between trait plasticity and resource conservatism contribute to the maintenance of alternative stable states? New Phytologist 223: 1809-1819.

Andrés-Sanchés S, Verboom GA, Galbany-Casals M, Bergh NG. 2019. Evolutionary history of the arid climate-adapted Helichrysum (Asteraceae: Gnaphalieae): Cape origin and association between annual life-history and low chromosome numbers. Journal of Systematics and Evolution 57: 468-487.

Zhigila DA, Verboom GA, Stirton CH, Smith HJ, Muasya AM. 2019. Six new Thesium (Santalaceae) species endemic to the Greater Cape Floristic Region, South Africa, and one new name. Phytotaxa 423: 215-237.

Cramer MD, Wootton LM, van Mazijk R, Verboom GA. 2019. New regionally modelled soil layers improve prediction of vegetation type relative to that based on global soil models. Diversity and Distributions 25: 1736-1750.

Chase BM, Boom A, Carr AS, Chevalier M, Quick LJ, Verboom GA, Reimer PJ. 2019. Extreme hydroclimate response gradients within the western Cape Floristic Region of South Africa since the Last Glacial Maximum. Quaternary Science Reviews 219: 297-307.

Zhigila DA, Verboom GA, Stirton CH, Muasya AM. 2019. A taxonomic revision of Thesium section Hagnothesium (Santalaceae) and descriptioon of a new species, T. quartzicolum. South African Journal of Botany 124: 280-303

Larridon I, Verboom GA, Muasya AM. 2018. Revised delimitation of the genus Tetraria, nom. Cons. Prop. (Cyperaceae, tribe Schoeneae, Tricostularia clade). South African Journal of Botany 118: 18-22.

Bergh NG, Verboom GA, Bentley J. 2018. Classification of the Relhania generic group (Asteraceae, Gnaphalieae) revisited using molecular phylogenetics. Phytotaxa 344.2.1.

Power SC, Verboom GA, Bond WJ, Cramer MD. 2017. Environmental correlates of biome-level floristic turnover in South Africa. Journal of Biogeography 44: 1745-1757.

Bentley J, Verboom GA, Bergh NG. 2017. Species-level phylogenetic analysis in the Relhania clade of “everlastings” and a new generic treatment of species previously assigned to Macowania and Arrowsmithia (Asteraceae: Gnaphalieae). Taxon 66: 1421-1438.

Larridon I, Verboom GA, Muasya AM. 2017. (2555) Proposal to conserve the name Tetraria (Cyperaceae) with a conserved type. Taxon 66: 1226-1227.

Boucher FC, Verboom GA, Musker SD, Ellis AG. 2017. Plant size: a key determinant of diversification? New Phytologist 216: 24-31.

Verboom GA, Stock WD, Cramer MD. 2017. Specialization to extremely low-nutrient soils limits the nutritional adaptability of plant lineages. The American Naturalist 189: 684-699.

Cramer MD, Verboom GA. 2017. Measures of biologically relevant environmental heterogeneity improve prediction of regional plant species richness. Journal of Biogeography 44: 579-591.

Verboom GA, Herron ML, Moncrieff GR, Slingsby JA. 2016. Maintenance of species integrity in the context of a recent radiation: the case of Jamesbrittenia (Scrophulariaceae: Limoselleae) in southern Africa. Botanical Journal of the Linnean Society 182: 115-139.

Linder HP, Verboom GA. 2015. Radiation of the southern African flora. Annual Review of Ecology, Evolution and Systematics 46: 393-412.

Bergh NG, Haiden SA, Verboom GA. 2015. Molecular phylogeny of the ‘Cape snow’ genus Syncarpha (Asteraceae: Gnaphalieae) reveals a need for generic re-delimitation. South African Journal of Botany 100: 219-227.

Hoffmann V, Verboom GA, Cotterill FPD. 2015. Neogene climate and landscape evolution in the Cape Floristic region of South Africa: insights from plant phylogeny. PLoS ONE 10: e0137847.

Verboom GA, Bergh NG, Haiden SA, Hoffmann V, Britton MN. 2015. Topography as a driver of diversification in the Cape Floristic Region. New Phytologist 207: 368-376.

Britton MN, Hedderson TA, Verboom GA. 2014. Topography as a driver of cryptic speciation in the high-elevation sedge Tetraria triangularis (Boeck.) C.B. Clarke (Cyperaceae: Schoeneae). Molecular Phylogenetics and Evolution 77: 96-109.

Slingsby JA, Britton MN, Verboom GA. 2014. Ecology limits the diversity of the Cape flora: phylogenetics and diversification of the genus Tetraria. Molecular Phylogenetics and Evolution 72: 61-70.

Bouchenak-Khelladi Y, Slingsby JA, Verboom GA, Bond WJ. 2014. Diversification of C4 grasses does not coincide with their ecological dominance. American Journal of Botany 101: 300-307.

Bentley J, Verboom GA, Bergh NG. 2014. Erosive processes after tectonic uplift stimulate vicariant and adaptive speciation: evolution in an Afrotemperate-endemic paper daisy genus. BMC Evolutionary Biology 14: 27.

Matimati I, Verboom GA, Cramer MD. 2014. Do hydraulic redistribution and nocturnal transpiration facilitate nutrient acquisition in Aspalathus linearis? Oecologia 175: 1129-1142.

Matimati I, Verboom GA, Cramer MD. 2014. Nitrogen regulation of transpiration controls mass-flow acquisition of nutrients. Journal of Experimental Botany 65: 159-168.

Viljoen J-A, Muasya AM, Barrett RL, Bruhl JJ, Gibbs AK, Slingsby JA, Wilson KA, Verboom GA. 2013. Radiation and repeated transoceanic dispersal of Schoeneae (Cyperaceae) through the Southern Hemisphere. American Journal of Botany 100: 2494-2508.

Verboom GA, Moore TE, Hoffmann V, Cramer MD. 2012. The roles of climate and nutrients in shaping life history traits in Cape grasses. Plant and Soil 355: 323-340.

Stock WD, Verboom GA. 2012. Phylogenetic ecology of foliar N, P and N:P ratios across Mediterranean type ecosystems. Global Ecology and Biogeography 21: 1147-1156.

Power SC, Cramer MD, Verboom GA, Chimphango SBM. 2011. Legume seeders of the Cape Floristic Region inhabit more fertile soils than congeneric resprouters – sometimes. Plant Ecology 212: 1979-1989.

Bergh NG, Trisos CH, Verboom GA. 2011. Phylogenetic relationships of Ifloga and Trichogyne (Compositae, Gnaphalieae) and resurrection of the genus Comptonanthus. Taxon 60: 1065-1075.

Bergh NG, Verboom GA. 2011. Anomalous capitulum structure and monoecy confer flexible sex allocation and life history evolution in the Ifloga lineage of paper daisies (Compositae: Gnaphalieae). American Journal of Botany 98: 1113-1127.

Warren BH, Bakker FT, Bellstedt DU, Bytebier B, Classen-Bockhoff R, Dreyer LL, Edwards D, Forest F, Galley C, Hardy CR, Linder HP, Muasya AM, Mummenhoff K, Oberlander KC, Quint M, Richardson JE, Savolainen V, Schrire BD, Van der Niet T, Verboom GA, Yesson C, Hawkins JA. 2011. Consistent phenological shifts in the making of a biodiversity hotspot: the Cape flora. BMC Evolutionary Biology 11: 39.

Power SC, Cramer MD, Verboom GA, Chimphango SBM. 2010. Does phosphate acquisition constrain legume persistence in the fynbos of the Cape Floristic Region? Plant and Soil 334: 33-46.

Linder HP, Baeza M, Barker NP, Galley C, Humphreys AM, Lloyd K, Orlovich D, Pirie MD, Simon BK, Walsh N, Verboom GA. 2010. A generic classification of the Danthonioideae (Poaceae). Annals of the Missouri Botanical Garden 97: 306-364.

Bouchenak-Khelladi Y, Verboom GA, Savolainen V, Hodkinson TR. 2010. Biogeography of the grasses (Poaceae): a phylogenetic approach to reveal evolutionary history in geographical space and time. Botanical Journal of the Linnean Society 162: 543-557.

Malgas RR, Potts AJ, Oettle NM, Koelle B, Todd SW, Verboom GA, Hoffman MT. 2010. Distribution, quantitative morphological variation and preliminary molecular analysis of different growth forms of wild rooibos (Aspalathus linearis) in the northern Cederberg and on the Bokkeveld Plateau. South African Journal of Botany 76: 72-81.

Moore TE, Verboom GA, Forest F. 2010. Phylogenetics and biogeography of the parasitic genus Thesium L. (Santalaceae), with an emphasis on the Cape of South Africa. Botanical Journal of the Linnean Society 162: 435-452.

Yates MJ, Verboom GA, Rebelo AG, Cramer MD. 2010. Ecophysiological significance of leaf size variation in Proteaceae from the Cape Floristic Region. Functional Ecology 24: 485-492.

Cramer MD, Hawkins H-J, Verboom GA. 2009. The importance of nutritional regulation of plant water flux. Oecologia 161: 15-24.

Bouchenak-Khelladi Y, Verboom GA, Hodkinson TR, Salamin N, Francois O, Chonghaile GN, Savolainen V. 2009. The origins and diversification of C4 grasses and savanna-adapted ungulates. Global Change Biology 15: 2397-2417.

Verboom GA, Dreyer LL, Savolainen V. 2009.  Understanding the origins and evolution of the world’s biodiversity hotspots: the biota of the African ‘Cape Floristic Region’ as a case study. Molecular Phylogenetics and Evolution 51: 1-4.

Verboom GA, Archibald JK, Bakker FT, Bellstedt DU, Conrad F, Dreyer LL, Forest F, Galley C, Goldblatt P, Henning JF, Mummenhoff K, Linder HP, Muasya AM, Oberlander KC, Savolainen V, Snijman DA, van der Niet T, Nowell TL. 2009. Origin and diversification of the Greater Cape flora: Ancient species repository, hotbed of recent radiation, or both? Molecular Phylogenetics and Evolution 51: 44-53.

Muasya AM, Simpson DA, Verboom GA, Goetghebeur P, Naczi RFC, Chase MW, Smets E. 2009. Phylogeny of Cyperaceae based on DNA sequence data: current progress and future prospects. The Botanical Review 75: 2-21.

Cramer MD, Hoffmann V, Verboom GA. 2008. Nutrient availability moderates transpiration in Ehrharta calycina. New Phytologist 179: 1048-1057.

Pirie MD, Humphreys AM, Galley C, Barker NP, Verboom GA, Orlovich D, Draffin SJ, Lloyd K, Baeza CM, Negritto M, Ruiz E, Cota Sanchez JH, Reimer E, Linder HP. 2008. A novel supermatrix approach improves resolution of phylogenetic relationships in a comprehensive sample of danthonioid grasses. Molecular Phylogenetics and Evolution 48: 1106-1119.

Hempson GP, February EC, Verboom GA. 2007. Determinants of Colophospermum mopane growth form in arid savannas. Austral Ecology 32: 429-435.

Trinder-Smith TH, Linder HP, van der Niet T, Verboom GA, Nowell TL. 2007. Plastid DNA sequences reveal generic paraphyly within Diosmeae (Rutoideae, Rutaceae). Systematic Botany 32: 847-855.

Barker NP, Galley C, Verboom GA, Mafa P, Gilbert M, Linder HP. 2007. The phylogeny of the austral grass subfamily Danthonioideae: evidence from multiple data sets. Plant Systematics and Evolution 264: 135-156.

Linder HP, Dlamini T, Henning J, Verboom GA. 2006. The evolutionary history of Melianthus (Melianthaceae), an enigmatic southern African shrub. American Journal of Botany 93: 1052-1064.

Slingsby JA, Verboom GA. 2006. Phylogenetic relatedness limits coexistence at fine spatial scales: evidence from the schoenoid sedges (Cyperaceae: Schoeneae) of the Cape Floristic Region, South Africa. The American Naturalist 168: 14-27.

Verboom GA, Ntsohi R, Barker NP. 2006. Molecular phylogeny of African Rytidosperma-affiliated danthonioid grasses reveals generic polyphyly and convergent evolution in spikelet morphology. Taxon 55: 337-348.

Verboom GA. 2006. A phylogeny of the schoenoid sedges (Cyperaceae: Schoeneae) based on plastid DNA sequences, with special reference to the genera found in Africa. Molecular Phylogenetics and Evolution 38: 79-89.

Verboom GA, Linder HP, Stock WD. 2004. Testing the adaptive nature of radiation: growth form and life history divergence in the African grass genus Ehrharta (Poaceae: Ehrhartoideae). American Journal of Botany 91: 1364-1370.

Stock WD, Chuba DK, Verboom GA. 2004. Distribution of South African C3 and C4 species of Cyperaceae in relation to climate and phylogeny. Austral Ecology 29: 313-319.

Verboom GA, Linder HP, Stock WD. 2003. Phylogenetics of the grass genus Ehrharta: evidence for radiation in the summer-arid zone of the South African Cape. Evolution 57: 1008-1021.

Verboom GA, Stock WD, Linder HP. 2002. Determinants of postfire flowering in the geophytic grass Ehrharta capensis. Functional Ecology 16: 705-713.

Verboom GA, Linder HP. 1998. A re-evaluation of species limits in Chaetobromus (Danthonieae: Poaceae). Nordic Journal of Botany 18: 57-77.

Linder HP, Verboom GA, Barker NP. 1997. Phylogeny and evolution in the Crinipes group of grasses (Arundinoideae: Poaceae). Kew Bulletin 52: 91-110.

Linder HP, Verboom GA. 1996. Generic limits in the Rytidosperma (Danthonieae, Poaceae) complex. Telopea 6: 597-627.

Verboom GA, Linder HP, Barker NP. 1994. Haustorial synergids: an important character in the systematics of danthonioid grasses (Arundinoideae: Poaceae)? American Journal of Botany 81: 1601-1610.

Peer-reviewed books and book chapters

Ellis AG, Verboom GA, van der Niet T, Johnson SD, Linder HP. 2014. Speciation and extinction in the Greater Cape Floristic Region. In: Allsopp N, Colville JF, Verboom GA (eds.), Fynbos: ecology, evolution and conservation of a megadiverse region, 119-142. Oxford University Press, Oxford.

Verboom GA, Linder HP, Forest F, Hoffmann V, Bergh NG, Cowling RM. 2014. Cenozoic assembly of the Greater Cape flora. In: Allsopp N, Colville JF, Verboom GA (eds.), Fynbos: ecology, evolution and conservation of a megadiverse region, 93-118. Oxford University Press, Oxford.

Bergh NG, Verboom GA, Rouget M, Cowling RM. 2014. Vegetation types of the Greater Cape Floristic Region. In: Allsopp N, Colville JF, Verboom GA (eds.), Fynbos: ecology, evolution and conservation of a megadiverse region, 1-25. Oxford University Press, Oxford.

Allsopp N, Colville JF, Verboom GA (eds.) 2014. Fynbos: ecology, evolution and conservation of a megadiverse region. Oxford University Press, Oxford.

Other publications

Verboom GA. 2010. A window onto the spectacular flora of South Africa. South African Journal of Science 106: 9. [BOOK REVIEW]

Verboom GA. 2003. Poaceae. In: TH Trinder-Smith, The Levyns guide to the plant genera of the southwestern Cape, Pp. 54-77. Contributions from the Bolus Herbarium 21. [FAMILY ACCOUNT IN FLORA]

De Roo R, Midgley J, Verboom T. 2003. Trianoptiles solitaria: the cryptic, curious Cape sedge. Veld and Flora 89: back cover. [POPULAR ARTICLE]